EP 0 557 847 B1 discloses a hearing aid which can be worn on the head, comprising an electrical signal path between a microphone and a receiver, in which the signal path can be adapted to different hearing situations/acoustic environments using means for electronically setting preprogrammable transmission parameters and a switching means for the hearing aid, with the switching means additionally controlling a signal emission device which emits at least one signal which is characteristic of the transmission parameter set for a specific hearing situation/acoustic environment, with the hearing aid user being able to perceive this signal and to be informed of the selected setting without removing the hearing aid from their head. This document also discloses that on first activation of a switching means within a predetermined period, only the signal emission device is enabled, as a result of which the user of the hearing aid receives information about the enabled transmission parameter without this being modified by activation of the switching means.
The use of digital actuators in particular for the manual setting of parameters in hearing aids is also known, said actuators not having a mechanical end stop.
DE 28 22 672 A1 discloses a function actuator for a computer-controlled message-related device. The known device has a knob with no mechanical stop. The values set are displayed by means of an LED chain.